Judging efficiency and effectiveness of a data visualisation
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. A visualisation is effective if viewers can...
2. Which measure best shows efficiency?
3. 10 of 10 test viewers read the right value from a chart, but it took each of them over two minutes. The chart is...
4. Viewers find the answer in 5 seconds, but 7 of 10 give the wrong answer. The chart is...
5. Which statement is a judgement backed by evidence?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1Effective visualisation | ACorrect answers show effectiveness, not efficiency. Efficiency needs evidence about time or effort, such as how many seconds testers took. | |
| 2Efficient visualisation | B4 of 5 testers named the correct region (80% correct) | |
| 3Evidence for efficiency: time taken by each tester to find the answer | CFast times show efficiency, not effectiveness. Effectiveness needs evidence that the answers were correct, which is not given. | |
| 4Evidence for effectiveness: how many testers gave the correct answer | DViewers find the answer quickly and with little effort | |
| 5All 5 testers answered correctly, so the dashboard is efficient. | ETester 1: 12 seconds, Tester 2: 9 seconds, Tester 3: 15 seconds | |
| 6Testers found the answer in 8 seconds, so the chart is effective. | FViewers answer the research question correctly after reading the visualisation |
C
Definitions
effectiveness and efficiency
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
=_______(B2:B9)
2.
=_______(C2:C9,"Correct")
3.
=COUNTIF(C2:C9,"Correct")/______(C2:C9)
4.
=___(B2:B9)
5.
IF avgTime __ 10 THEN
verdict ← "Efficient"
END IF
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
correct ← 18
B
total ← correct
C
rate ← correct / total * 100
D
PRINT rate
Question 2
A
times ← [12, 9, 15, 8]
B
sum ← 0
C
FOR EACH t IN times
D
sum ← sum + 1
E
END FOR
F
avg ← sum / LENGTH(times)
Question 3
A
avgTime ← 8
B
IF avgTime >= 10 THEN
C
PRINT "Efficient"
D
END IF
Question 4
A
IF correctRate >= 80 THEN
B
verdict ← "Efficient"
C
ELSE
D
verdict ← "Not effective"
Question 5
A
taken ← endTime + startTime
B
PRINT taken
C
IF taken < 10 THEN
D
PRINT "Quick to use"
Answer Key
Judging efficiency and effectiveness of a data visualisation
Section A: Quick Questions
Q1
B — Answer the research question correctly
Q2
B — The time viewers take to find an answer
Q3
A — Effective but not efficient
Q4
A — Efficient but not effective
Q5
A — The dashboard is effective: 9 of 10 testers correctly named the top region
Section B: Match the Pairs
Q1
Effective visualisation → Viewers answer the research question correctly after reading the visualisation
Q2
Efficient visualisation → Viewers find the answer quickly and with little effort
Q3
Evidence for efficiency: time taken by each tester to find the answer → Tester 1: 12 seconds, Tester 2: 9 seconds, Tester 3: 15 seconds
Q4
Evidence for effectiveness: how many testers gave the correct answer → 4 of 5 testers named the correct region (80% correct)
Q5
All 5 testers answered correctly, so the dashboard is efficient. → Correct answers show effectiveness, not efficiency. Efficiency needs evidence about time or effort, such as how many seconds testers took.
Q6
Testers found the answer in 8 seconds, so the chart is effective. → Fast times show efficiency, not effectiveness. Effectiveness needs evidence that the answers were correct, which is not given.
Section C: Definitions
Q1
effectiveness and efficiency — Effective = viewers answer the research question correctly. Efficient = they answer quickly, with little effort. Back each judgement with evidence, like test times.Section D: Fill in the Blanks
Q1
=AVERAGE(B2:B9)Q2
=COUNTIF(C2:C9,"Correct")Q3
=COUNTIF(C2:C9,"Correct")/COUNTA(C2:C9)Q4
=MAX(B2:B9)Q5
IF avgTime <= 10 THEN
verdict ← "Efficient"
END IFSection E: Spot the Error
Q1
B — Effectiveness is the share of viewers who answered correctly out of everyone tested. Setting total to correct makes the rate always 100%. It should be total ← 20.
Q2
D — Efficiency is judged by the time viewers take, so each test time must be added to the total. Adding 1 only counts viewers. It should be sum ← sum + t.
Q3
B — A visualisation is efficient when viewers find answers quickly, so the average time must be at or below the target. It should be IF avgTime <= 10 THEN.
Q4
B — A high rate of correct answers shows the visualisation is effective, not efficient. Efficiency is about time and effort. It should be verdict ← "Effective".
Q5
A — The time to find an answer is the end time minus the start time. Adding them gives a meaningless value. It should be taken ← endTime - startTime.